| Year | Value | | 2022 | 17,715 | | 2021 | 17,328 | | 2020 | 16,949 | | 2019 | 16,516 | | 2018 | 16,028 | | 2017 | 15,569 | | 2016 | 15,143 | | 2015 | 14,682 | | 2014 | 14,214 | | 2013 | 13,792 | | 2012 | 13,360 | | 2011 | 12,910 | | 2010 | 12,517 | | 2009 | 12,190 | | 2008 | 11,937 | | 2007 | 11,740 | | 2006 | 11,571 | | 2005 | 11,425 | | 2004 | 11,286 | | 2003 | 11,141 | | 2002 | 10,989 | | 2001 | 10,839 | | 2000 | 10,704 | | 1999 | 10,579 | | 1998 | 10,454 | | 1997 | 10,335 | | 1996 | 10,224 | | 1995 | 10,114 | | 1994 | 10,006 | | 1993 | 9,901 | | 1992 | 9,796 | | 1991 | 9,695 | | 1990 | 9,598 | | 1989 | 9,505 | | 1988 | 9,415 | | 1987 | 9,325 | | 1986 | 9,237 | | 1985 | 9,153 | | 1984 | 9,073 | | 1983 | 8,995 | | 1982 | 8,923 | | 1981 | 8,853 | | 1980 | 8,783 | | 1979 | 8,712 | | 1978 | 8,641 | | 1977 | 8,570 | | 1976 | 8,500 | | 1975 | 8,430 | | 1974 | 8,360 | | 1973 | 8,290 | | 1972 | 8,218 | | 1971 | 8,144 | | 1970 | 8,068 | | 1969 | 7,990 | | 1968 | 7,919 | | 1967 | 7,853 | | 1966 | 7,787 | | 1965 | 7,720 | | 1964 | 7,655 | | 1963 | 7,591 | | 1962 | 7,524 | | 1961 | 7,455 | | 1960 | 7,387 |
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